The administration of therapeutic agents by aerosol means is well known in the art and a number of aerosol inhalation devices are known (see, for example, Chapter 92, "Aerosols" in Remington's Pharmaceutical Sciences 18th Edition, pages 1694-1712, Mack Publishing Co., Easton, Pa., 1990). Fixed aerosol actuator devices of one-piece construction of the type, for example, disclosed in U.S. Pat. Nos. 3,918,451; 3,991,761; 4,011,864; 4,069,819, 4,227,522; 4,265,236; 4,454,877; 4,576,157; 4,648,393; 4,860,740; 5,002,048; 5,012,804; 5,115,803; 5,134,993; 5,134,993; 5,161,524; and 5,178,138 are well known.
Devices which are articulated and which can be folded or telescoped for convenient carrying in a pocket or purse have also been described in the prior art. Devices of this type are disclosed in U.S. Pat. Nos. 3,739,950; 3,788,316; 3,927,806; 3,994,421; 4,130,116; 4,292,966; 4,509,515; 4,637,528; and 4,641,644.
For the most part, these devices are of a design which does not address a problem with aerosol inhalation actuator devices; namely, the retention of considerable amounts of the aerosol particulates in the expansion chamber of the device or in the throat of the patient when each dose of medicament is delivered.
Sioutas (U.S. Pat. No. 5,115,803) discusses the problem, and discloses a fixed-type aerosol actuator in which the cannister-receiving portion of the device and the exit chamber are at right angles to one another, connected by a chamber having a spherical internal surface.